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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

Vacuum Line

  • Thread starter Thread starter rotorhead22
  • Start date Start date Oct 1, 2021

rotorhead22

Active Member
Dec 17, 2020
175
89
38
Wesley Chapel, Florida
Oct 1, 2021
#1
  • Oct 1, 2021
  • #1
I have a 1989 LX with a broken vacuum line that I cannot figure out where the other end goes. It is part of the A/C system and I have looked at several diagrams however I just dont see where it connects to.
 

revhead347

Apparently my ex-husband made that mistake.
20+ Year Stangneter
Jun 14, 2004
9,303
1,648
214
Acworth, GA
Oct 1, 2021
#2
  • Oct 1, 2021
  • #2
Bear with me, because it's been years since i have owned a Fox. There should be a black line that comes out through the firewall right around where the AC gas lines go through.

Kurt
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,295
17,998
224
Massachusetts
Oct 1, 2021
#3
  • Oct 1, 2021
  • #3
It runs out to the fender where there is a small vaccum ball. It holds a vacuum reserve for the HVAC so your vent settings don’t randomly change as you lose vacuum at WOT
 
Reactions: Gs1987GT, rotorhead22 and Wayne Waldrep

mattys91gt

Active Member
Feb 3, 2022
391
26
38
Plymouth Massachusetts
May 2, 2022
#4
  • May 2, 2022
  • #4
Mustang5L5 said:
It runs out to the fender where there is a small vaccum ball. It holds a vacuum reserve for the HVAC so your vent settings don’t randomly change as you lose vacuum at WOT
Click to expand...
how do you have your EGR lines running and the evr I think it's called on the strut tower
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,295
17,998
224
Massachusetts
May 2, 2022
#5
  • May 2, 2022
  • #5
mattys91gt said:
how do you have your EGR lines running and the evr I think it's called on the strut tower
Click to expand...

My current setup is not really factory OEM, so showing pics would be confusing.

It’s rather simple though. Your source is one of the hard nipples on the vac tree in the backside of the intake manifold. That line runs over to the EVR and then you run a line back to the EGr.

Supply the EVR with pure vacuum and then it regulates the vacuum to the egr as needed. Nothing complex and it’s separate from other systems
 
Reactions: mattys91gt

mattys91gt

Active Member
Feb 3, 2022
391
26
38
Plymouth Massachusetts
May 2, 2022
#6
  • May 2, 2022
  • #6
Mustang5L5 said:
My current setup is not really factory OEM, so showing pics would be confusing.

It’s rather simple though. Your source is one of the hard nipples on the vac tree in the backside of the intake manifold. That line runs over to the EVR and then you run a line back to the EGr.

Supply the EVR with pure vacuum and then it regulates the vacuum to the egr as needed. Nothing complex and it’s separate from other systems
Click to expand...
I pulled my lines off thinking the EGR went with the smog system it's my first mustang and to many YouTube videos it was running fine till I touched it now it idles horrible and at wot u feel it buck as u go faster just tiny ones nothing crazy my issue is the 2 lines coming out the bottom of the strut I know ones for HVAC my heater core is bypassed and ac don't work will that make my engine bay hotter with the heater core bypassed also sorry I get off track
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,295
17,998
224
Massachusetts
May 2, 2022
#7
  • May 2, 2022
  • #7
Pull those lines off and cap them. You’ll get codes by with the vacuum source capped the car should still run fine.
 
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